Fig. 30.—Skeleton of Triceratops prorsus; length about 25 feet. (After Marsh.)
In this Dinosaur we find the fore feet larger than usual in proportion to the hind limbs, and there can be no doubt that it walked on all fours. Its length was about twenty-five feet. All the vertebræ and limb-bones are solid. The brain was smaller in proportion to the skull than in any known vertebrate.
The teeth are remarkable in having two distinct roots. The wedge-like form of the skull is also very peculiar. The two large horns come immediately over the eyes, and the small one above the nose; this Dinosaur was, therefore, well provided with weapons of offence, such as would be highly useful in driving away or wounding carnivorous enemies. The back part of the skull rises up into a kind of huge crest, and this during life was protected by a special fringe of bony plates. Such an arrangement doubtless formed an effective shield to ward off blows when one Triceratops was fighting another, as bulls or buffaloes of the present day fight with their horns. The mouths of these Dinosaurs formed a kind of beak, sheathed in horn.
The body as well as the skull was protected, but the nature and position of the defensive parts in different forms cannot yet be determined with certainty. Various spines, bones, and plates have been found that evidently were meant for the protection of the creature’s body, and belonged to the skin. Probably some of these were placed on the back, behind the crest of the skull; some may have defended the throat, as in Stegosaurus. Altogether, Triceratops is very different to any other Dinosaur. One cannot help picturing it rather as a fierce rhinoceros-like animal. In the restoration ([Plate XI., Frontispiece]) our artist has given it a thick skin, rather like that of the rhinoceros, only indicating small bony plates, etc., here and there.
Professor Marsh thinks that as the head increased in size to bear its armour of bony plates, the neck first, then the fore feet, and then the whole skeleton was specially modified to support it; and he concludes that as these changes took place in the course of the evolution of this wonderful Dinosaur, the head at last became so large and heavy that it must have been too much for the body to bear, and so have led to its destruction! This conclusion, if sound, is a warning against carrying “specialisation” too far. If we wished to write an epitaph on the tomb of the monster, it ought (according to Professor Marsh) to be, “I and my race died of over-specialisation.”